An energy source in necessary to provide power for propelling a vehicle. For example, petroleum based products, such as gasoline or diesel, are the main energy source of conventional vehicles that include internal combustion engines. On the other hand, electrified vehicles are known that utilize one or more electric machines and in some cases an engine that can be used either individually or in combination to propel the vehicle. A high voltage battery typically acts as one energy source for powering such electric machines.
It may be beneficial to calculate the energy use of a vehicle in order to display a variety of end use features to the vehicle driver. For example, an energy consumption rate may be monitored and used to predict a distance to empty (DTE) value which can be displayed to the vehicle driver to provide information for trip planning, minimizing driving costs, evaluating vehicle performance, etc. One current method used to monitor energy use of a vehicle is a time domain approach. However, other approaches may provide improvements to existing methods.